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1.
Biomass, carbon content, carbon storage and spatial distribution in the 32-year-old Phoebe bournei artificial forest were measured. The mean biomass of the forest stand was 174.33 t/hm2, among which the arbor layer was 166.73 t/hm2, which accounted for 95.6%. Carbon contents of stems, barks, branches, leaves, root, shrub layer, herb layer, lichen layer and litter layer were 0.5769 g C/g, 0.4654 g C/g, 0.5232 g C/g, 0.4958 g C/g, 0.4931 g C/g, 0.4989 g C/g, 0.4733 g C/g, 0.4143 g C/g, 0.3882 g C/g, respectively. The mean carbon content of soil was 0.0139 g C/g, which reduced gradually along with soil depth. Total carbon storage of the P. bournei stand ecosystem was 227.59 t/hm2, among which the arbor layer accounted for 40.13% (91.33 t/hm2), the shrub layer accounted for 0.17% (0.38 t/hm2), the herb layer accounted for 0.76% (1.71 t/hm2), the lichen layer accounted for 0.28% (0.63 t/hm2), and the litter layer accounted for 0.29% (0.66 t/hm2). Carbon content (0–80 cm) of the forest soil was 58.40% (132.88 t/hm2). Spatial distribution ranking of carbon storage was: soil layer (0–80 cm) > arbor layer > herb layer > litter layer > lichen layer > shrub layer. Net production of the forest stand was 8.5706 t/(hm2·a), in which the arbor layer was 6.6691 t/(hm2·a), and it accounted for 77.82%. Net annual carbon sequestration of the P. bournei stand was 4.2536 t/(hm2·a), and the arbor layer was 3.5736 t/(hm2·a), which accounted for 84.01%. __________ Translated from Scientia Silvae Sinicae, 2008, 44(3): 34–39 [译自: 林业科学]  相似文献   

2.
对海南岛尖峰岭35年生鸡毛松人工林生物量的结构与分布特点、净初级生产力和林分生长的动态变化进行了研究。结果表明,鸡毛松人工林乔木层生物量达285 53t·hm-2,其中树干为190 82t·hm-2,树皮为19 19t·hm-2,树枝为35 93t·hm-2,树叶为7 96t·hm-2,根为31 63t·hm-2,鸡毛松不同器官生物量的比例为树干∶树枝∶根∶树皮∶树叶=24 0∶4 5∶4 0∶2 4∶1 0。12～22cm径级的立木生物量占总生物量的70 9%,而8m以下的树干生物量占其总生物量的80%以上。1～25a内生物量增长迅速,年平均净生产量随年龄的增加而增大,25a后生物量增长相对较慢,进入生长的平稳期。35a鸡毛松人工林乔木层年平均净生产力可达10 34t·hm-2·a-1,最大可达13 99t·hm-2·a-1,表现出较高的生产力。  相似文献   

3.
红树林是热带、亚热带海岸潮间带的木本植物群落,它是海湾河口地区生态系统最重要的生产者,对保护海湾河口地区的生态平衡起着十分重要的作用。湿地植物生物量是衡量湿地生态系统健康状况的重要标志。红树林生物量的研究,对于了  相似文献   

4.
The biomass and net primary production of Mongolian scotch pine (Pinus sylvestris L. var.mongolica) plantations of west Kerqin sandy land were measured. According to average standard trees, the biomass, net primary production and their distributions of trunk, bark, branch, leaf and root of 16-year-old stand were analyzed. The regressive equation for the estimation of each organ biomass was established through dimensional analysis. Preferable equation with higher precision was selected. The study results showed that the total biomass of the forest community was 62.023 t/hm2 and net primary production was 5.045 t/(hm2·a), which indicates that the community of plantation possesses high bio-productivity. (Responsible Editor: Chai Ruihai)  相似文献   

5.
六盘山主要植被类型的生物量及其分配   总被引：6，自引：3，他引：3       下载免费PDF全文
2009年,在宁夏六盘山南部林区香水河小流域,调查研究了主要森林类型的生物量及其层次和器官分配。结果表明:不同森林的活体植被总生物量(t·hm-2)差别较大,依次为华山松(102.70)>桦木林(84.42)>山杨林(79.97)>华北落叶松人工林(58.37)>疏林(44.91),按各类森林面积加权平均为78.37,远高于灌丛(20.77)、草地(1.07)和草甸(2.29)。各类森林的枯落物现存量(t·hm-2)为:华北落叶松人工林(18.21)>华山松林(11.99)>桦木林(10.90)>山杨林(7.67)>疏林(7.06),也都远高于灌木林(3.13)、草甸(0.82)和草地(0.49)。森林生物量集中在乔木层(占91.04%),灌木层仅占8.09%,草本层更低至0.87%。森林生物量的器官分配比例:乔木层为树干(54.06%)>枝(21.04%)>根(16.92%)>皮(5.34%)>叶(2.65%);灌木层为枝干(62.68%)>根(30.55%)>叶(6.77%);草本层为地上茎叶(58.82%)>根(41.18%)。乔木层地上与地下生物量比值的平均值为4.49,几种阔叶林都在4.0左右,但华北落叶松林为6.41,华山松林为5.80,都远大于灌木林的2.82、草地的1.89及草甸的1.20。不同林分的生物量均随林龄和林冠郁闭度的增大而几乎线性增加,并随林分密度的增加而增大,但在密度超过900株·hm-2后生物量增速减缓并渐趋其最大值。  相似文献   

6.
[目的]研究兴安落叶松生物量增长率对氮沉降是否存在响应,年际间是否存在差异;不同径级是否会影响兴安落叶松生物量增长率对氮沉降的响应。[方法]通过人工氮添加的方法模拟大气氮沉降变化,探究兴安落叶松林连续3年(2014—2016)树木生物量的变化对氮沉降的响应。从2012年开始,共设置4个氮添加水平,分别为对照(CK,0 g·m-2·a-1)、低氮(TL,2.5 g·m-2·a-1)、中氮(TM,5 g·m-2·a-1)和高氮(TH,7.5 g·m-2·a-1),每年的生长季(5—10月)按月将NH4NO3溶于32 L蒸馏水,利用背喷式喷雾器均匀喷洒于样方内,对照样地喷洒等量纯净水。[结果](1)3年间各施氮处理生物量增长率均显著高于对照组(P0.05)、各年份生物量增长率均存在显著差异(P0.05),而且2016年生物量增长率明显高于前两年(P0.05)。(2)2014年各处理间无显著差异;2015年TL处理的生物量增长率显著高于TM和TH处理(P0.05),2016年TL处理的生物量增长率显著高于TH处理(P0.05)。(3)不同处理对年际间不同径级生物量增长率也产生不同影响。TL处理对2014和2016年的10 15cm径级的兴安落叶松生物量增长率有显著促进作用(P0.05);TM处理对所有年份10 15 cm和15 20 cm径级兴安落叶松生物量增长率均有显著促进作用(P0.05);TH处理对所有年份胸径大于10 cm的3个径级(1015、15 20、20 cm)兴安落叶松生物量增长率均有显著促进作用(P0.05)。[结论](1)长期氮添加有可能导致树木生长率的增量逐渐减少甚至出现抑制,将改变现有北方森林生态系统碳源汇动态;(2)由于不同径级树木对氮沉降的响应不同,为提高氮沉降对北方森林碳库影响的模型预测精度,应按不同径级分别模拟。  相似文献   

7.
The role of canopy interception on nutrient cycling in Chinese fir plantation ecosystem was studied on the basis of the position data during four years. Results indicate that the average canopy interception amount was 267.0 mm/year. Canopy interception play a significant role in water cycle and nutrient cycle processes in ecosystem, and was an important part of evaporation from the Chinese fir plantation ecosystem, being up to 27.2%. The evaporation from the canopy interception was an important way of water output from ecosystem, up to 19.9%. The flush-eluviation of branches and leaves caused by canopy interception brought nutrient input of 143.629 kg/(hm2 · year), which was 117.2% of the input 63.924 kg/(hm2 · year) from the atmospheric precipitation. The decreased amount of 80.1 mm precipitation input caused by canopy interception reduced the amount of rainfall into the stand surface and infiltration into the soil, reduced the output with runoff and drainage, and decreased nutrient loss through output water. Therefore, the additional preserve of nutrient by canopy interception was 8.664 kg/(hm2 · year). __________ Translated from Scientia Silvae Sinicae, 2006, 42(12): 1–5 [译自: 林业科学]  相似文献   

8.
The Maoershan forestry centre is situated in the Zhangguangcai Mountain of the Changbai mountain range. The main forest types in the Maoershan region are plantation (Pinus sylvestris var. mongolica, Pinus koraiensis and Larix gmelinii) and natural secondary forests (Fraxinus mandshurica, Quercus mongolica and Populus davidiana). Fine roots have enormous surface areas, growing and turning over quickly, which plays an important role in terms of substance cycling and energy flow in the forest ecosystem. This study deals with the dynamics of live, dead, and total fine roots (≤ 5 mm) biomass in the 0–30 cm soil layer using the soil core method. Differences between the six stands in the Maoershan region showed the following results: 1) the fine root biomass in the various stands showed obvious differences. The total fine root biomass of six stands from high to low were F. mandshurica (1,030.0 g/m2) > Q. mongolica (973.4 g/m2) > Pinus koraiensis (780.9 g/m2) > L. gmelinii (718.2 g/m2) > Populus davidiana (709.1 g/m2) > Pinus sylvestris var. mongolica (470.4 g/m2); 2) except for L. gmelinii, the development of live fine root biomass agreed with the trend of total fine root biomass. The maximum biomass of live fine roots in Pinus koraiensis or L. gmelinii stand appeared in May, others in June; in the F. mandshurica stand, the minimum biomass of live fine roots occurred in September, others in July or August; 3) the proportions of dead fine root biomass varied in different stands; 4) the vertical distribution of fine roots was affected by temperature, water, and nutrients; the proportion of fine root biomass was concentrated in the 0–10 cm soil layer. The fine root biomass of six stands in the 0–10 cm soil layer was over 40% of the total fine root biomass; this proportion was 60.3% in F. mandshurica. Space-time dynamics of the various stands had different characteristics. When investigating the substance cycling and energy flows of all forest ecosystems, we should consider the characteristics of different stands in order to improve the precision of our estimates. __________ Translated from Scientia Silvae Sinicae, 2006, 42(6): 13–19 [译自: 林业科学]  相似文献   

9.
A study was conducted to test the correlation between biomass and elevation and the differences in concentration and storks of nutrients among five vegetation types （Felsenmeer alpine tundra vegetation-FA, Lithic alpine tundra vegetation-LA, Typical alpine tundra vegetation-TA, Meadow alpine tundra vegetation-MA, and Swamp alpine tundra vegetation-SA） on alpine tundra of Changbai Mountains, Jilin Province, China in growing seasons of 2003, 2004 and 2005. The biomass of 43 mono-species and soil nutrients in alpine tundra ecosystem were also investigated. Dominant species from Ericaceae （such as Rhododendron chrysanthum and Vaccinium jliginosum var. alpinum） were taken to analyze organ biomass distribution. Result showed that the biomass and elevation had a significant correlation （Biomass-237.3 in（Elevation） ＋494.36; R^2=0.8092; P〈0.05）. No significant differences were found in phosphorus and sulphur concentrations of roots, stems and leaves among the five vegetation types. There were significant differences in nitrogen and phosphorus stocks of roots, stems and leaves and in sulphur stock of stems and leaves among TA, MA, and SA vegetation types （p〈0.05）. The nutrient stock of five vegetations was averagely 72.46 kg.hm^-2, of which N, P, S were 48.55, 10.33 and 13.61 kg·hm^-2, respectively. Soil N and S concentrations in meadow alpine tundra soil type was significantly higher than those in other four soil types （Cold desert alpine tundra soil, Lithic alpine tundra soil, Peat alpine tundra soil, and Gray alpine tundra soil）. Phosphorous concentration in SA type was higher （p〈0.05） than in other types. Soil nutrient stock （0-20cm） was averagely 39.59 t.hm^-2, of which N, P, S were 23.74, 5.86, 9.99 t·hm^-2, respectively.  相似文献   

10.
2003
  • Wallenstein M D.McNulty S.Fernandez I J.Boggs J Schlesinger W H Nitrogen fertilization decreases forest soil fungal and bacterial biomass in three long-term experiments [其它论文] 2006
  • Wang X F.Li S Y.Bai K J.Kuang T Y Influence of doubled CO2 on plant growth and soil microbial biomass C and N 1998(12)
  • Xue J H.Mo J M.Li J.Li D J The short-term response of soil microorganism number to simulated nitrogen deposition 2007(02)
  • Yao W H.Yu Z Y The nutrient content of throughfall inside the artificial forests on downland 1995
  • Yi Z G.Yi W M.Zhou L X.Wang X M Soil microbial biomass of the main forests in Dinghushan Biosphere Reserve 2005(05)
  • Zhou G Y.Yan J H The influence of region atmospheric precipitation characteristics and its element inputs on the existence and development of Dinghushan forest ecosystems [其它论文] -Acta Ecologica Sinica2001

    • >>更多...  相似文献   


    11.
    造林密度对米老排人工林初期生长的影响   总被引：1，自引：0，他引：1       下载免费PDF全文
    [目的]探讨不同造林密度对米老排人工林生长的影响规律,为米老排人工林定向培育过程中的密度控制提供参考。[方法]以广东省云浮市造林后6年生米老排人工林为研究对象,对不同造林密度(625、833、1 111、1 667、2 500株·hm~(-2))林分平均树高、优势木高、胸径、保留率和枝下高等生长指标进行连续4年调查。[结果]表明:随着造林密度的增大,米老排林分平均胸径、胸径连年生长量、保留率、单株材积和材积连年生长量均显著减小,而枝下高、林分蓄积量和蓄积连年生长量显著增加。在一定密度范围内,造林密度对林分高生长的影响比较小。造林后第6年,密度1 667株·hm~(-2)林分的平均树高最大(11.4 m),优势木高以密度1 111株·hm~(-2)林分的最大(13.3m),树高连年生长量以密度625株·hm~(-2)林分的最大(1.5 m·a~(-1));密度625株·hm~(-2)林分的平均胸径、胸径连年生长量、单株材积和材积连年生长量均最大,分别为14.3 cm、2.5 cm·a~(-1)、0.097 3 m~3和0.038 2 m~3·a~(-1),比密度2 500株·hm~(-2)林分的分别增加27.7%、81.0%、49.0%和82.4%;密度2 500株·hm~(-2)林分的枝下高、蓄积量和蓄积连年生长量均最大,分别为6.0 m、149.4 m~3·hm~(-2)和44.8 m~3·hm~(-2)·a~(-1),分别是密度625株·hm~(-2)林分的2.61、2.52、1.95倍。[结论]分析了造林密度对米老排初期生长的影响,对米老排人工林的培育具有理论指导意义。  相似文献   

    12.
    杉木人工林水土流失及养分损耗研究   总被引：23，自引：4，他引：19       下载免费PDF全文
    １９８４～１９９６年在江西分宜县中国林科院亚热带林业实验中心的３个林场,分别对杉木人工林幼龄林、中龄林及近熟林进行了８组水土保持及养分循环方面多点的试验观测,对杉木人工林水土流失及养分损耗作了研究。结果表明,杉木人工林水土流失以幼林阶段为最大,其次中龄林阶段,最小是近熟林阶段。幼龄林地表迳流量为５４６．０ｍ＾３．ｈｍ＾－２,土壤侵蚀总量为１０５０．０ｋｇ．ｈｍ＾－２,土壤侵蚀量尤为明显;中龄林地表迳流量为５０６．９８ｍ＾３．ｈｍ＾－２;而近熟林地表迳流量为４７７．２５ｍ＾３．ｈｍ＾－２,土壤侵蚀量可略而不计。幼龄林流失有机质５０．０４９ｋｇ．ｈｍ＾－２,养分为３１．５０８ｋｇ．ｈｍ＾－２;中龄林流失有机质为６．０８０ｋｇ．ｈｍ＾－２,养分流失量为２．０９６ｋｇ．ｈｍ＾－２,而近熟林养分流失量为１０．７８４ｋｇ．  相似文献   

    13.
    English yew Taxus baccata L. has been catalogued as endangered tree species and prone to extinction in Austria as well as many other parts of Europe. The present work is based on the comparison of the natural population of two gene conservation forests from different geographic locations in Austria where the spatial structure, regeneration status and possible conservation measures are examined. The pole stand distribution varied distinctly in each sites. The total no of individuals per ha （DBH ≥5 cm）, average DBH and average height were 492 n.hm^-2, 8.8 cm and 6.3 m in Stiwollgraben whereas in Leininger Riese 45 n.hm^-2, 16.3 cm and 7.6 m respectively. Over 79% of the Stiwollgraben population were represented the good health condition, while in Leininger Riese it was less then 49 % which means population of Stiwollgraben is in better condition compared to Leininger Riese. The sites differed considerably in the pattern of regeneration but pattern were consistent with the dynamics depicted by the age distribution. Considering the one-year-old seedlings Stiwollgraben contains 13 019 individuals.hm^-2 whereas Leininger Riese only 1 368. Surprisingly there were no any saplings in respect of 51 to 150 cm height classes in both sites and 30 to 50 cm in Stiwollgraben. In that context the conservation of English yew on the forest level may require well-managed reserves and long-term rotations between harvest events, protection from the herbivore and reduction of competition, which will enhance the long-term viability of the species.  相似文献   

    14.
    [目的]为了阐明森林凋落物累积量与主要影响因子的关系。[方法]2013-2014年,采用时空互代法和标准样地调查法,研究了兴隆山山杨-白桦-青杄林演替过程中山杨-白桦-青杄中龄林、青杄中龄林和青杄近熟林3种森林群落凋落物累积量及其主要影响因子。[结果]表明:1)随森林正向演替的进行,森林凋落物层厚度和总累积量先减小后增加,3种森林群落凋落物层厚度均值依次为5.26、5.03和5.59 cm,总累积量均值依次为57.08、51.44、56.34 t·hm-2; 2)随海拔高度的升高,青杄近熟林凋落物总累积量不断增加,海拔2300、2400和2500 m均值依次为48.56、55.93和64.55 t·hm-2;林分密度大的、坡度小的青杄中龄林凋落物总累积量较大,林分密度为2133、1705和1065株·hm-2的均值依次为49.87、48.59和45.36 t·hm-2,坡度为22°、32°和41°的均值依次为58.35、49.90和48.59 t·hm-2; 3)凋落物未分解层与林分胸径、树高、针叶树密度呈显著相关性。[结论]森林凋落物累积量影响因子较多,其大小是众多因子共同作用的结果。在林分和立地因子中,海拔影响较为明显,随海拔高度的升高而不断增加;林分密度、坡度等因子均有影响,但作用不明显;林分胸径、树高、针叶树密度与未分解层累积量呈显著负相关性,而与已分解层呈显著正相关性。  相似文献   

    15.
    长白落叶松人工林生物量的结构与分布   总被引：1，自引：0，他引：1  
    采用径级标准木和样方收获法,对24a生长白落叶松人工林的生物量和生产力进行了研究。结果表明:24a生长白落叶松人工林分生物量为120.55t/hm2,年平均净生产力为8.47 t/(hm2.a),生态系统的生物量分配格局为乔木层>枯枝落叶层>下木层>草本层,其中乔木层生物量为102.17t/hm2,净生产力为8.09t/(hm2.a),其生物量分配格局为树干>树根>树皮>树枝>树叶;在林分产量结构方面,8 m以下树干生物量占其总量的81.80%,树枝和树叶的生物量主要分布在10～14 m,分别占树枝和树叶总生物量的71.11%和73.05%,地下根系生物量分配格局为粗根(直径大于5 cm)>根头>中根(0.5～5 cm)>细根(<0.5cm),粗根生物量占根总生物量的53.98%。  相似文献   

    16.
    Hurricanes cause abrupt carbon reduction in forests, but silviculture treatment can be an effective means of quickly regenerating and restoring hurricane-damaged sites. This study assessed how silviculture treatments affect carbon balance after hurricane damage in central Hokkaido, Japan. We examined carbon storage in trees and underground vegetation as well as carbon emissions from silviculture operations in 25-year-old stands, where scarification and plantation occurred just after hurricane damage. The amount of carbon stored varied according to silviculture treatment. Among three scarification treatments, a scarified depth of 0 cm (understory vegetation removal) led to the largest amount of carbon stored (64.7 t·ha-1 C). Among four plantation treatments, the largest amount of carbon was stored in a Larix hybrid (L. gmelinii var. japonica × L. kaempferi) plantation (80.3 t·ha-1 C). The plantation of Abies sachalinensis was not successful at accumulating carbon (40.5·ha-1 C). The amount of carbon emitted from silviculture operations was 0.05-0.14 t·ha-1 C, and it marginally affected the net carbon balance of the silviculture project. Results indicate that silviculture treatments should beperformed in an appropriate way to effectively recover the ability of carbon sequestration in hurricane-damaged forests.  相似文献   

    17.
    For this paper, we studied the water-holding capacity of canopy, vegetation layer under canopy and litter layer, the water-holding capacity and permeability of soil as well as their changes with growth of stands in Acacia mangium plantations of three different age classes (four-, seven-and 11-year-old). Results show that total water-holding above ground in the order of 11-year stand age (52.86 t/hm2)>seven-year stand age (41.90 t/hm2)>seven-year stand age (25.78 t/hm2), the increment tendency increased with stand age. Similar sequence also obtained on the water-holding capacity and permeation capacity of soil (0–40 cm). The total water-storage capacity both above ground and soil in four-year-old, seven-year-old and 11-year-old of A. mangium plantations were 2,023.0, 2,158.4 and 2,260.4 t/hm2, respectively, and the all value of water conservation were 1,372.70, 1,474.42 and 1,549.91 yuan (RMB)/hm2, respectively. Therefore, A. mangium plantation had a good ability to modify soil structure and good water conservation function. __________ Translated from Journal of Soil and Water Conservation, 2006, 20(5): 5–8, 27 [译自: 水土保持学报]  相似文献   

    18.
    Regressive models of the aboveground biomass for three conifers in subtropical China—slash pine (Pinus elliottii), Masson pine (P. massoniana) and Chinese fir (Cunninghamia lanceolata)—were established. Regression analysis of leaf biomass and total biomass of each branch against branch diameter (d), branch length (L), d 3 and d 2 L was conducted with functions of linear, power and exponent. A power law equation with a single parameter (d) was proved to be better than the rest for Masson pine and Chinese fir, and a linear equation with parameter (d 3) is better for slash pine. The canopy biomass was derived by adopting the regression equations to all branches of each individual tree. These kinds of equations were also used to fit the relationship between total tree biomass, branch biomass, foliage biomass and tree diameter at breast height (D), tree height (H), D 3 and D 2 H, respectively. D 2 H was found to be the best parameter for estimating total biomass. However, for foliage biomass and branch biomass, both parameters and equation forms showed some differences among species. Correlations were highly significant (P<0.001) for foliage biomass, branch biomass and total biomass, among which the equation of the total biomass was the highest. With these equations, the aboveground biomass of Masson pine forest, slash pine forest and Chinese fir forest were estimated, in addition to the allocation of aboveground biomass. The above-ground biomass of Masson pine forest, slash pine forest and Chinese fir forest was 83.6, 72.1 and 59 t/hm2 respectively, and the stem biomass was more than the foliage biomass and the branch biomass. The underground biomass of these three forests which estimated with others’ research were 10.44, 9.42 and 11.48 t/hm2, and the amount of carbon-fixed were 47.94, 45.14 and 37.52 t/hm2, respectively. __________ Translated from Chinese Journal of Applied Ecology, 2006, 17(8): 1382–1388 [译自: 应用生态学报]  相似文献   

    19.
    西藏南伊沟林芝云杉林生物量与生产力研究   总被引：3，自引：1，他引：2       下载免费PDF全文
    采用样地调查及标准样木收获法,研究西藏米林南伊沟成熟林芝云杉(Picea likiangensis var.linzhiensis林乔木层、灌木层、草本层、死亡木、凋落物层的生物量与生产力及其分配规律.结果表明:林芝云杉林生态系统总的生物量为367.49 t·hm-2,其中乔木层生物量最高276.64 t·hm-2,占总生物量的75.28％,其次是凋落层的生物量40.65 t·hm-2,占总生物量的11.06％.在乔木层中,干材生物量201.23 t·hm-2 (69.32％),皮25.53 t·hm-2(8.79％),枝17.80 t·hm-2(6.13％),叶3.33 t·hm-2(1.15％),根42.87 t·hm-2(14.61％).随着树木的生长,干材生物量所占比例增大,而枝、叶的比例则减小.林芝云杉林生态系统生产力为10.65 t·hm-2·a-1,其中乔木层最高5.00 t·hm-2·a-1,占总生产力的46.94％,其次为凋落层3.40 t·hm-2·a-1,占总生产力31.94％.在乔木层中仍以树干生产力最大2.58 t·hm-2 ·a-1,依次为枝(0.89 t·hm-2·a-1)、叶(0.67t·hm-2·a-1)、根(0.54t·hm-2·a-1)、皮(0.33 t·hm-2 ·a-1).  相似文献   

    20.
    不同栽培措施对尾巨桉生长的影响及经济效益分析   总被引：20，自引：2，他引：18       下载免费PDF全文
    试验采用列区试验设计,设造林密度和追肥2个因素,每个因素6个水平,4次重复.密度因子作主区,追肥因子作副区,各个因素和各处理按随机区组排列.每个试验小区面积0.04 hm2(20 m×20 m),共计144个小区,连续5 a观测.经过方差分析得出,造林试密度对林分平均高、平均胸径和蓄积量都有极显著的影响.在6种参试密度中,造林密度越大,林分平均高、胸径越小,蓄积量越大;6种配方追肥对林分平均高影响不显著,对胸径和蓄积量生长影响显著;密度与追肥的交互作用不显著.在所有36个列区试验组合中,按经济效益排列前5名的密度和追肥最佳组合分别为:2 222株.hm-2和每公顷施N、P、K分别为200、150、100 kg,1 667株.hm-2和每公顷施N、P、K分别为300、200、200 kg;1 667株.hm-2和每公顷施N、P、K分别为200、150、100 kg;2 222株.hm-2和每公顷施N、P、K分别为100、50、50 kg;1 250株.hm-2和每公顷施N、P、K分别为200、150、100 kg.它们的蓄积量分别为183.94、188.43、169.95、164.33、163.03 m3.hm-2;利润值分别为14 977.44、14 965.09、13 832.83、13 785.80和13 345.18元.hm-2.  相似文献   

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